Conversion of hydrocarbon oils



July 25, 1939. J. B. HEID CONVERSION OF HYDROCARBON'OILS Filed Oct. 12,1935 mm mmm wnzou INVENTOR TORNEY m E H m M A J N E B C A J PatentedJuly 25, 1939 UNITED STATES ATENT OFFICE Jacob B. Heid, Chicago, lll.,assigner to Universal Oil Products Company, Chicago, lill., acorporation of Delaware Application October 152, 1935, Serial No. 44,646

3 Claims.

This invention particularly refers to an improved process for theselective conversion of hydrocarbon oil charging stock for the process,residual liquid resulting from said conversion, 5 and intermediateliquid products of both cracking operations, for the production of majoryields of desirable light distillate, such as motor fuel of goodantiknock value, and minor yields of good quality residual liquid orcoke and gas.

In one specic embodiment, the present invention comprises subjectinghydrocarbon oil charging stock for the process to conversion conditionsof cracking temperature and superatmospheric pressure in a heating coil,introducing the resulting heated products into a reduced pressurevaporizing chamber wherein separation of vaporous and liquid conversionproducts is accomplished, withdrawing liquid conversion products fromsaid vaporizing chamber, subjecting the same to independently controlledconversion conditions of cracking temperature and superatmosphericpressure in a separate heating coil, introducing the heated productsfrom said separate heating coil into another vaporizing and separatingor coking chamber, wherein the final residual liquid conversion productof the process is separated from vaporous conversion products, andeither withdrawn from the system or reduced therein to coke, supplyingthe vaporous conversion products from said separate vaporizing andseparating chamber to the first mentioned vaporizing and separatingchamber, wherein high boiling components of the vapors are condensed,collected with the liquid conversion products from the iirst mentionedcracking step, and supplied therewith to said separate heating coil,withdrawing vaporous conversion products remaining uncondensed from thefirst mentioned vaporizing and separating chamber, subjecting the sameto fractionation for the formation of reux condensate, subjectingfractionated vapors of the desired end boiling point to condensation,co1- lecting and separating the resulting distillate and gas, subjectingsaid reflux condensate to independently controlled conversion conditionsof cracking temperature and superatmospheric pressure in anotherseparate heating coil and communicating enlarged reaction chamber,withdrawing both vaporous and liquid conversion products from saidreaction chamber, and introducing the same into said separate Vaporizingand separating chamber.

As an alternative to the method of operation above outlined, whichhowever is not to be considered equivalent, the heated products from thelast mentioned heating coil, instead of being subjected to continuedconversion in a high pressure reaction chamber, may be supplied, all orin part, direct to said separate vaporizing and separating chamber. Onthe other hand, the heated products from both the second mentioned andlast mentioned heating coils may, when desired, be supplied to thereaction chamber for further conversion.

It is also within the scope of the invention, particularly in case thecharging stock comprises an oil of relatively high boilingcharacteristics or contains a relatively large proportion of highboiling materials, to eliminate the first-mentioned heating coil and tosupply the charging stock directly to the first mentioned vaporizingchamber, wherein it is subjected to substantial Vaporization by Contactwith the hot vaporous products from said separate vaporizing andseparating chamber.

The accompanying diagrammatic drawing illustrates one specific form ofapparatus for carrying out the invention.

Referring to the drawing, hydrocarbon oil charging stock for the processis supplied through line l and valve 2 to pump 3, by means of which itis fed through line 4 and may be directed through valve 5 in this lineto heating coil 6. Heating coil Ei is located within a furnace 1 of anysuitable form, by means of which the required heat is supplied to theoil passing through the heating coil to subject the same to the desiredconversion conditions of cracking temperature and superatmosphericpressure in this Zone. The heated products are discharged from heatingcoil 6 through line 8 and valve 9 into vaporizing and separating chamberIt. It will be understood, of course, that'the charging stock may, whendesired, be preheated in any well known manner not villustrated in thedrawing to any desired temperature below that at which substantialconversion thereof will occur prior to its introduction into heatingcoil 6.

Chamber may be operated at any desirable pressure ranging from pounds orthereabouts 45 per square inch superatmcspheric down to substantiallyatmospheric pressure and is preferably operated at a substantiallyreduced pressure relative to that employed in the outlet from theheating coil.v Separation of the vaporous and liquid conversion productsfrom this zone is accomplished in chamber l0 by means oi' theircontained heat assisted by their reduction in pressure. The relativelyhigh boiling liquids remaining unvaporized in chamber l@ are withdrawn55 from the lower portion of this zone through line E3 and valve M topump l5, by means of which they are supplied through line I6 and valveil to conversion in heating coil i3 under independently controlledconversion conditions of cracking temperature and superatmosphericpressure. Heat for conversion of the relatively high boiling oil,passing through heating coil I8, is supplied thereto from a furnace i9of any suitable form, and heated products from this zone are directedthrough line 2G, and valve 2l into another vaporizing and separatingchamber 23.

Chamber 23 is preferably operated at a substantially reduced pressurerelative to that employed at the outlet from heating coil i8, whichhowever is somewhat higher than the pressure employed in chamber I0.Separation of vaporous and residual liquid conversion products isaccomplished in chamber 23. The latter may be withdrawn from the lowerportion of this Zone and directed through line 24 and valve 25 tocooling and storage, or elsewhere as desired, or when desired they maybe reduced in chamber 23 to substantially dry coke. In the latter case,the coke may be allowed to accumulate within chamber 23, to be removedtherefrom in any well known manner not illustrated after this Zone hasbeen substantially lled with coke or after its operation has beencompleted for any other reason, and after it has been isolated from therest of the process. It will be understood that a plurality of cokingchambers may be employed, when desired, although not illustrated, inwhich case they preferably are alternately operated, cleaned andprepared for further operation. In case coking is employed in chamber23, line 24 may serve as a drain line and may also serve, when desired,as a means of introducing steam, water or other suitable coolingmaterial into the chamber in order to hasten cooling and facilitateremoval of coke.

The vaporous conversion products supplied to chamber 23, as well as anyvapors evolved in this zone, are Withdrawn from the upper portionthereof and directed through line 26 and valve 2T into chamber l0,wherein they commingle with the charging stock or with the conversionproducts from heating coil 6, and wherein any heavy components of thevaporous products unsuitable for conversion, together with reuxcondensate, may be separated therefrom and supplied, together with otherheavy liquids from this Zone, to conversion in heating coil I8, aspreviously described.

The total vaporous conversion products of the process remaininguncondensed in chamber lil are withdrawn from the upper portion thereofand directed through line 28 and valve 29 to fractionation infractionator 33. The components of vapors supplied to fractionator 3Bboiling above the range of the desired final light distillate product ofthe process are condensed in this zone as reflux condensate.Fractionated vapors of the desired end boiling point are withdrawn,together with uncondensable gas produced in the operation, from theupper portion of fractionator 3) and are directed through line Si andvalve 32 to condensation and cooling in condenser 33, The resultingdistillate and gas passes through line and valve 35 to collection andseparation in receiver 35. Uncondensable gas may be released from thereceiver through line 3l and valve 38. Distillate may be withdrawn fromreceiver 35 through line 39 and valve #i9 to storage or to any desiredfurther treatment.

When desired, a regulated portion of the distillate collected inreceiver E@ may be recirculated by well known means (not illustrated) tothe upper portion of fractionatcr 3i! to serve as a cooling and reuxingmedium in this zone for assisting fractionation of the vapors and tomaintain the desired vapor outlet temp ature.

The reflux condensate formed in ac"onator 30 may be withdrawn from thelow portion of this zone through line #il and valve to pump 43, by meansof which it is fed through line lli and valve (l to heating coil d5.

Heating coil l5 is located in a furnace l? of any suitable form, bymeans of which heat is supplied to the oil passing through the heatingcoil to subject the same to independently controlled conversionconditions of cracl "ng temperature and superatmospheric pressure. Theheated products are discharged from heating coil 46 through line 48 andare directed through valve 49 in this line into reaction chamber 5l.

It is also within the scope of the present invention, when desired, tointroduce all or a regulated portion of the heated products from heatingcoil I8 into reaction chamber 5l by means of line 2li', valve 22 andline 49.

Reactie-n chamber is preforably maintained at a substantialsuperatmospheric pressure which may be substantially the same orsomewhat lower than the pressure employed at the outlet from heatingcoil ilil, or from heating coil i8 in case products from the latter zoneare supplied to the reaction chamber and heating coil i8 is operated ata lower pressure than that employed in heating coil 46. The conversionproducts supplied to the reaction chamber, and particularly theirvaporous components, are subjected to appreciable further conversion, inthis Zone, and preferably although not illustrated is insulated in orderto conserve heat. In the case here illustrated both vaporous andconversion products are withdrawn in commingled state from the lowerportion of chamber 5l and are directed through line 53, valve 5d, intochamber 23.

The preferred range of operating conditions which may be employed inaccordance with the process of the present invention utilizing anapparatus such as illustrated and above described may be approximatelyas follows: The heating coil wherein the charging stock is subjected toconversion may employ an outlet conversion temperature ranging forexample from 800 to 950 F., preferably with a superatmospheric pressureat this point in the system of from 100 to 500 pounds or more per squareinch. The succeeding vaporizing chamber, as previously mentioned, ispreferably operated at a substantially reduced pressure, which may rangefor example from 100 pounds per sduareinch superatrnospheric pressuredown to substantially atmospheric pressure, and the pressure employed inthis zone may be substantially equalized or reduced in succeedingfractionating, condensing and collecting portions of the system. Theheating coil to which the residual liquid from said vaporizing chamberis supplied may utilize an outlet conversion temperature ranging forexample from 800 to 1000 F'. or thereabouts, preferably with asuperatmospheric pressure at the outlet from this zone ranging from 30pounds or thereabouts per square inch to 300 pounds or more per squareinch. The heating coil to which the reflux condensate is supplied forconversion may utilize an outlet temperature ranging for example from900 to 1000 F., preferably with a superatrnospheric pressure at thispoint in the system of from 200 to 800 pounds or more'per square inch.The reaction chamber, as previously mentioned, may be operated at aatmospheric pressure substantially the same or somewhat lower than thatemployed in the preceding heating coil utilizing the lowest pressure.The vaporizing or coking chamber to which products fromthe reactionchamber are supplied, in case the reaction chamber is utilized, isoperated at a superatmospheric pressure of from 30 to 100pounds,`orthereabouts, per square inc h, which however is somewhathigher than the pressurev4 employed in the first mentioned vaporizingchamber, and is preferably somewhat lower than the pressure employed inthe reaction chamber or in the preceding heating coils.

As a specific example of the operation of the process of the presentinvention as it may be accomplished in an apparatus such as illustratedand above described, the charging stock, which comprises a 30 A. P, I.gravity Mid-Continent topped crude, is subjected in the rst heating coilto an outlet conversion temperature of approximately 930 F. at asuperatmospheric pressure of about 300 pounds per square inch, and thesucceeding vaporizing chamber to which the products from this heatingcoil are supplied is operated at a superatmospheric pressure ofapproximately 50 pounds per square inch. The liquid products from thisvaporizing chamber are quickly heated in a separate heating coil to anoutlet conversion temperature of approximately 980 F. at asuperatmospheric pressure of about 60 pounds per square inch and areintroduced into a coking chamber maintained at substantially the samepressure. The reflux condensate is heated in another separate heatingcoil to an outlet conversion temperature of approximately 950 F. at aatmospheric pressure of about 350 pounds per square inch, and the heatedproducts from this zone are introduced into a reaction chambermaintained at substantially the same pressure. Both vaporous and liquidproducts from the reaction chamber are supplied to the coking chamber.Vaporous products from the coking chamber are supplied to the samevaporizing chamber to which the heated products from the charging stockheating coil are supplied, and the vaporous products from this zone aresubjected to fractionation for the formation of reux condensate andrecovery of desirable light distillate. This operation will yield, perbarrel of charging stock, approximately of motor fuel of good anti-knockvalue, and approximately 75 pounds of low volatile coke, the remainderbeing chargeable principally to uncondensable gas.

I claim as my invention:

l.. A process for the conversion of hydrocarbon oils, which comprisessubjecting hydrocarbon oil charging stock for the process to crackingtemperature and superatmospheric pressure in a heating coil, introducingthe heated products into a reduced pressure vaporizing chamber whereinvaporous and liquid conversion products are separated, withdrawing thelatter from the vaporizing chamber and subjecting the same toindependently controlled conditions of cracking temperature andsuperatmospheric pressure in a separate heating coil, introducing heatedproducts from said separate heating coil into a colring chamber whereinthe non-vaporous high-boiling conversion products are reduced to coke,Withdrawing the vaporous products from the coking chamber andintroducing the same into the vaporizingand separating chamber,subjecting vaporous products from the vaporizing and separating chamberto fractionation for the formation of reux condensate comprising theirinsufficiently converted components, subjecting fractionated vapors ofthe desired end boiling point to condensation, recovering the resultingdistillate, subjecting reux condensate formed by said fractionationtoindependentIy controlled conversion conditions of cracking temperatureand superatmospheric pressure in another separate heating coil andcommunicating enlarged reaction chamber, and introducing both vaporousand liquid conversion products from the reaction chamber into the cokingchamber, the process being further characterized in that at least aregulated portion of the heated products from the second-mentionedheating coil is passed through said reaction chamber prior to theirintroduction to the coking chamber.

2. In a process for the conversion of hydrocarbon oils, wherein refluxcondensate, comprising insufficiently converted intermediate liquidconversion products of the process, is subjected to conversionconditions of cracking temperature and superatmospheric pressure in aheating coil and communicating reaction chamber, both vaporous andliquid conversion products withdrawn from the reaction chamber andintroduced into a coking chamber wherein their high-boiling nonvaporouscomponents are reduced to coke, the improvement which comprisesintroducing vaporousproducts from the coking chamber into a vaporizingand separating chamber, simultaneously heating hydrocarbon oil chargingstock for the process to cracking temperature under pressure in aseparate heating coil and then introducing the same to said vaporizingand sepa.- rating chamber, wherein it is contacted with the hot vaporousproducts from the coking chamber, withdrawing unVapo-rized high-boilingfractions of the charging stock and high-boiling components of thevaporous products, which are condensed in the vaporizing and separatingchamber, from the latter zone, subjecting the same to independentlycontrolled conversion conditions of cracking temperature andsuperatmospheric pressure in another separate heating coil, introducingseparate portions of the resulting heated products into the reactionchamber and into the coking chamber, withdrawing vaporous components ofthe charging stock and components of the vaporous` products from thecoking chamber remaining uncondensed in the vaporizing chamber from thelatter zone, subjecting the same to fractionation for the formation ofsaid reflux condensate, subjecting fractionated vapors of the desiredend boiling point to condensation, and recovering the resultingdistillate.

3. In a process for the conversion of hydrocarbon oils, wherein refluxcondensate, comprising insufficiently converted intermediate liquidconversion products of the process, is subjected to conversionconditions of cracking temperature and superatmospheric pressure in aheating coil and communicating reaction chamber, both vaporous andliquid conversion products withdrawn from the reaction chamber andintroduced into a reduced pressure vaporizing and separating chamber,wherein vaporous and residual liquid conversion products are separated,and the latter recovered, the improvement which comprises introducingvaporous products from the Vaporizing and separating chamber into asecond vaporizing and separating chamber, simultaneousing temperatureand superatmospheric pressure in another separate heating coil,introducing sep arate portions of the resulting heated products into thereaction chamber and into. said reduced pressure chamber, withdrawingcommingled charging oil vapors and cracked vapors from said secondvaporizing chamber, subjecting the same to fractionation for theformation of said reflux condensate, subjecting fractionated vapors ofthe desired end boiling point to condensation, and recovering theresulting distillate.

JACOB B. HEID.

